Roof Trusses - Nail To Interior Walls???

nailkiller1

I was just discussing this topic with my truss salesman a couple months ago
I first asked what is his recommended method of install
He gave me the whole story about the clips and Sheetrock floating

I have never used this system or have I had any truss uplift(approximately 30 new homes that i did a 1 year walk through
I have also framed a bunch of other houses( I may have never heard anything on those jobs even if their were issues)

So I asked him and the other salesman if they have seen any of these problems
They both had one or two stories from the last ten years
All of those homes were ho contracted they couldn't be sure it was even truss uplift

I have put crown moulding in two homes built in the 70s or 80s both with trusses
every winter the trusses on the bearing wall in one area curl up and come off the plate about a half inch(very odd) spring, back down crown looks good again

This would be a lot easier to incorporate into the system if their were some problems that i could see( my area)
Right now in my area I just don't see any reason to do the clip system
(I may change my mind tomorrow, framing a house in two weeks)

Willie T

It's on page 68.

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Bill Everett - St. Petersburg, FL

M. A. Hansen Co

It really does depend on the designed uplift in your area. I know when I build it houses on the coast in Florida hardware was a must have. Not only that but it had to be the right gauge hardware for that trusses specific uplift design. I know frame in Minnesota and most of the inspectors could care less so!

But after seeing three hurricanes in Florida use the hardware over the nails they work!

Rory Read

We use a lot of metal in our Seismic D portion of the Pacific Northwest.

I have only been a contractor for about 6 years, and most of my work has been remodeling. I have probably framed less than 10 houses.

Every truss I have ever seen seated gets clipped. What can happen is they get tagged "temporarily" when you are laying them out, and then you forget to pull those nails before you are done.

The clips are so easy to install and so cheap, and just the way it's done, so from here it's interesting to hear strong objections to the practice.

We are using even more metal than before, drywall clips instead of blocking and header hangers instead of jack studs, all in the name of reducing thermal bridging, using less wood, and the whole "advanced framing" thing.

Cjeff

I have seen truss uplift causing up to 3/8 inch gap. I have started switching to either blockinh or drywall clips (not commonly available in my area.
And yes many of the older carpenters do not understand it.

Warren

OK, I have seen and heard all of the discussion here and some in the field. We work in NE OH in a hot/cold changing climate. I have seen a few issues of ceiling/wall separation in my time. I have always nailed trusses down tothe interior walls. While this may not prevent the separation completely, it does seem to minimize it. I have worked with roof truss designers and engineers for 25 years. I haven't heard too much about this in the last ten years. Not sure if they have something in the engineering now that helps prevent it or not. My main concerns are as follows; While I understand that the truss wants to move, will installing the nails reduce the movement? Will reducing the movement, somehow adversely affect the truss structure? Again, I have not seen or heard of this being a big issue for some time now, and have done some very large homes with some crazy truss designs.

Chris@Sunrise

Our engineering shows the deflection of the trusses. I looked thru the last house we framed and the deflection values were all less than 1/4 inch and only the simple trusses had deflection the cut up valley hip trusses had none. But on the building where now framing that i mentioned earlier those 58 ft trusses allow for 1 1/8 in deflection. Maybe dtc clips arent needed but they sure make sense in truss deflction issues. I also talked to a designer after i posted and asked about this. He said they do pay attention to deflection alot more now and keep it minimal so nailing off to interiors on there trusses wouldnt matter one way or another. Should have talked to him first however he still said clips are the best way to ensure deflection is a non issue.

Warren

I would have to think that most of that 1 1/8 deflection would occur during construction. On big trusses like that I don't think nailing is gonna prevent them from uplifting anyway. I just wonder if it adversely affects the trusses in any way to nail them down.

Chris@Sunrise

Warren
Ill have to ask about that maybe if i have time ill call tommorow. That could well be the pre loaded to loaded deflection. We have 1/2 air space between top plate and trusses with a dtc clip every truss and the walls that run parrellel typical backer but then dtc clips to blocking every 48 in. Im thinking that the deflection is to allow snow load here. Its roofed and theres still a very visable crown to them. Nailing on trusses with that much deflection would just tear the cord apart may be thats what there saying is destructive to the trusses if the nailing does tear the cord that would alter the truss.????

Warren

I don't think thats it. Think about it, how bad could you split that out out in the middle like that? I think what the fear is ,is that if a truss is not allowed to move in a predetermined area, it will move somewhere else. Kind of like the uplift issue we deal with sometimes on 3 point bearing loads when the center load is not dead center. Often times this requires us to strap the ends. Also, I can't imagine that a snow load is gonna add that much more than the load of the entire roof structure, trusses, sheathing, shingles.

LighthouseConst

we always have toe-nailed to interior walls leaving the nails out atleast 1/2 inch to allow for movement in the trusses same as uplift clips

Cache

If you want a rule of thumb, I would say to just use the clips unless truss co. tells you to nail direct to the cap plate. The cracks you are talking about at the corners are avoidable. Floating corners perform better than those that have been completely nailed off to both walls and the ceiling. Essentially, the clips talked about here are a way to provide a floating joint at the ceiling and allow for truss uplift. Honestly, it is a good idea to make that the standard building practice, unless the truss co. says otherwise.

We have extreme temp swings here, and the most common call back it cracked out drywall and crown molding.

Cache

Intentionally leave a nail up 1/2" for wood to slide up and down? Too many pops and squeaks for me. Our temp swings 40* from the low just before sunrise to the high just before sunset on a daily basis. 105* in the summer, 30* below zero in the winter. A house like that would be popping and cracking like a bowl of rice crispies in this climate.

Static Design

This is what happens in KY when ppl nail off trusses........... My trusses crack and pop like crazy and gas heat doesn't help much either: but common practice around here is his daddy did it this way and mine also so this is how we frame.

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cbrew

It dose not matter if you nail thetrusses to the top plate or not. The sheet rock on the walls goes up tight to the ceiling. This keeps the trusses from deflecting under load. Most cracking is caused by wet lumber or improper sheet rock installation.

Burns-Built

I suppose what your saying is the wall rock will keep the truss from deflecting down?? But the truss will move up and down so when it goes up your cieling is going to go with it. The wall is going to stay put the inside corner fails..and WALA you have a nice gap between the cieling and wall. If the truss only deflected down you would be right, but it doesnt. So it does matter.

Use the clips, don't nail it, It could sqeeeeekkk, and you'll sleep better if you just do it right.

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Burns-Built

Unless.......

You let that last 16"s or so float, but then you would need the clips or a block such as THOM suggested, but you didn't mention that so i asssume your screwing the drwall at the edge of the cieliing next to your top plate to which your truss is thoroughly nailed.

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grafcustom

cbrew might have had a few too many brews...

Its been said already, but truss uplift is chronic in our area due to extreme swings in humidity and temp throughout the year.

Get a truss loaded and it will drop, to an extent yes. Increase humidy or temp or both it will also drop, THEN LIFT AGAIN when it dries or gets colder.

It is the variation to be concerned about. SIMPSON STC clips all the way with SIMPSON DS clips. Quicker and cheaper overall to install than hard blocking.

katoman

Here we use the clips. No nails within 18" of the wall. I do believe that the quality of the truss lumber plays into it somewhat.

Truss lift is a real event, especially with todays homes getting more insulation in the ceilings.

I recently had to fix a ceiling where the tape had pulled away due to truss lift. I use a small magnet to find the DW screws. They were 4" off the wall. Removed the screws, patch and paint and done.

LighthouseConst

ive never heard problems with tack nails, you should be using resiliant channel on trusses anyways. trusses arent straight and the channel allows for movement without cracking the corners